Synthesis and Characterization of Niobium, Tantalum and Uranium Precursors for Metal Oxide Depositions

This thesis primarly deals with the synthesis of in chemical vapor depositions usable, pentavalent niobium and tantalum complexes. In the first part of this thesis the synthesis of heteroleptic compounds with trifluoroheteroaryl-alkenolates or -acetamides starting from niobium or tantalum-iso-propoxide is described. The prepared compounds were examined in detail regarding their decomposition behavior and were subsequently decomposed to niobium or tantalum oxide by chemical vapor depositions, where the impact of ligand and substrate temperature on morphology and phase of the deposits was investigated.

In the second part of this work homoleptic and air stable trifluoroheteroaryl-alkenolates of uranium in the oxidation state +IV were prepared and thoroughly characterized. One of these compounds could be used as single source precursor for the plasma enhanced chemical vapor deposition of uranium(IV)oxide for the first time. The oxidation behavior of the synthesized thin film was examined as well.

In the last part of this thesis a suitable synthetic protocol for the synthesis of heterobimetallic niobium and tantalum alkoxides in combination with tetravalent transition metals and lanthanides was established. The isostructural compounds are the first examples of volatile niobium or tantalum containing bimetallic alkoxides.